Winnetka
EPA ID: IL0313330 · 12,475 people served · 3 ZIP codes
ZipCheckup's reading of EPA records for Winnetka (IL0313330): no drinking-water violations recorded since 2021. Water monitoring for Winnetka: no violations on record, 12,475 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Winnetka Source: EPA SDWIS service area boundaries.
Service area boundary - average Home Safety grade of mapped ZIPs: B
Demographics of ZIP Codes Served
The ZIP codes associated with Winnetka have a median household income of $230,777 and about 50,068 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 82% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: On average, 46% of census tracts in the counties mapped to this service area are designated disadvantaged by the federal Climate and Economic Justice Screening Tool (CEJST, 2022 version). Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
🌊 Where Does Your Water Come From?
Winnetka's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in Illinois
System Overview
Winnetka (EPA ID: IL0313330) is a community water system in Illinois that serves approximately 12,475 people from surface water sources.
This system provides water to 3 ZIP codes across 3 communities.
ZIP-Area Home Safety Context: B (70/100)
This is the average Home Safety Score for 1 of 3 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0085 mg/L | No | 2025-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
3 of 3 ZIP records with known zones are in EPA Radon Zone 2.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by IL or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for Winnetka (IL0313330) on EPA.gov.
Frequently Asked Questions
Is Winnetka water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Winnetka in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Winnetka serve?
Winnetka serves approximately 12,475 people across 3 ZIP codes in Illinois.
Where does Winnetka get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: No PFAS Reported Above Reporting Levels
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were reported above UCMR5 minimum reporting levels.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Winnetka, IL: Serves 12K People. https://zipcheckup.com/water-system/il0313330/
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title = {{Winnetka, IL: Serves 12K People}},
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url = {https://zipcheckup.com/water-system/il0313330/}
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